In recent decades, electrically driven pumps have been widely used in heat circulating systems. Currently, the heat circulating systems are developed in a trend of high performance, and compactification, accordingly, the electrically driven pump has a limited mounting space, and has requirements for high performance. Since the electrically driven pump has a small overall dimension and a small volume, the electrically driven pump includes an impeller, a diameter of the impeller is required to be small, in this case, a conventional impeller can hardly meet the requirements for high lift and high efficiency at low specific speed and low flow rate.
Therefore, it is necessary to improve the conventional technology, to address the above technical issues.